This invention relates to control systems for vapor-discharge lamps and, more particularly, to a control system which automatically dims the lamps after a predetermined time when a lower degree of illumination can be tolerated.
In recent years much effort has been directed toward developing lighting systems that are energy-conserving. Much energy is wasted by present day outdoor lighting systems, such as those used for street lighting and parking areas because these systems were not designed to operate at more than one power consumption level. There have been attempts to conserve energy with these present systems such as, turning a portion of the lights in a system completely off. This approach though conserving energy may be a safety hazard because of the poor lighting distribution that may result. The present invention constitutes an improvement over such an approach, in that, it provides for automatic dimming of an entire lighting system with uniform light distribution.